1. Field of the Invention
This invention relates to a polarizer labelling tape which is used for successively supplying plate-like polarizer elements onto liquid crystal panels. The present invention also relates to a method for making such a tape.
2. Description of the Prior Art
In a liquid crystal display device, the liquid crystal panel is sandwiched between a pair of plate-like polarizer elements. The pair of polarizer elements cooperate with the liquid crystal for allowing or interrupting light passage through the display device at selected dots for making an intended display of an image.
There are mainly two conventional methods of attaching a plate-like polarizer element to each surface of a liquid crystal panel.
A first conventional method utilizes a polarizer chip, as shown in FIG. 17 of the accompanying drawings. Specifically, the polarizer chip comprises a single plate-like polarizer element 61 interposed between a protective cover 62 and a releasable sheet 63. The polarizer element 61 has a size equal to that of a liquid crystal panel to which it is applied.
Due to difficulty of peeling the releasable sheet 63 at the time of mounting the polarizer chip to a surface of the liquid crystal panel, the releasable sheet 63 is first brought into attachment to a peeling adhesive sheet (not shown) which has a higher adhesion than the releasable sheet 63. When the polarizer chip is forcibly pulled away from the peeling adhesive sheet, the releasable sheet is adhered to the peeling adhesive sheet, thereby enabling mounting of the polarizer chip to the relevant surface of the liquid crystal panel.
Obviously, the use of the polarizer chip is disadvantageous in that the peeling adhesive tape is additionally needed for mounting the chip to the liquid crystal panel, thereby resulting in a production cost increase and difficulty of automation. Further, when a plurality of such chips need be successively mounted, the chips must be handled separately, consequently leading to a low productivity.
As shown in FIG. 18, a second conventional method utilizes a releasable tape 71' to which a plurality of plate-like polarizer elements 61' each covered by a protective film 62' are attached. The use of such a tape eliminates the problem of separately handling the polarizer elements 61'.
However, each of the polarizer elements 61' is originally attached to its own releasable sheet (like the prior art of FIG. 17) which is peeled off before attachment to the releasable tape 71'. Thus, the releasable tape 71 is an additional element which causes a production cost increase. Further, the need for peeling the original releasable sheet before attachment to the tape is also a time-taking step.